It is proposed to chemically examine Hawaiian marine algae, two species in particulr, for contained antibiotics and/or antitumor agents. About fifty different species of Hawaiian marine algae have been screened in the past year for antibiotic materials, and at least a half dozen of these appear to be worthy of further study. From the species Laurencia nidifica, two halogen-containing organic compounds have already been identified. Several other organic halides are present in the extract of this algae. These will be isolated and their structures determined. Dictyota acutiloba, a Hawaiian brown algae, also contains antibiotic material, and has been reported by earlier workers to contain antitumor factors as well. This algae yields large amounts of ether-soluble material, which will be fractionated and the more abundant components, as well as the biologically-active components, will be chemically investigated.